Recovery of tocopherol



Patented May 23, 1944 RECOVERY OF TOCOPHEROL Kenneth C. D. Hickman,Rochester, N. Y., assignor to Distillation Products, Inc., Rochester, N.Y., a corporation of Delaware No Drawing. Application March 2, 1940,Serial No. 321,913

13 Claims.

This invention relates to improved procedure for preparing and employingantioxidants to improved antioxidant products and stabilized substancesand the like.

It is a common procedure to subject various vegetable and animal oils,fats, and the like to refining treatment in order to improve color,taste, odor, etc. It has been recognized that refined oils have ratherpoor keeping qualities and that they are decidedly inferior in thisrespect to the raw or crude oils. The refining treatments employed inmost cases involved reaction with chemicals and deodorization in avacuum with inert gases such as steam. The inert gas treatment in vacuumis usually the final step in the refining process with the possibleexception of those cases where the oil is to be bleached.

This invention has for its object to provide improved antioxidants.Another object is to provide antioxidants which are satisfactory foredible materials. A further object is to provide improved procedure forstabilizing unstable or oxidizable substances, particularly foods andthe like. Another object is to provide improved procedure for preparingtocopherol antioxidants. Other objects are to provide improvements inthe art of stabilizing materials and preparation of antioxidants. Otherobjects will appear hereinafter.

It is well known that during the deodorization of fats and the like byvacuum and inert gas treatment, such as steam, a small amount ofvolatile matter is obtained as a distillate or impurity in thedistillate. When steam is employed for deodorizing, the materialseparates as a scum on the top of the water in the discharge from thebarometric ondenser. I have discovered that this material w en obtainedfrom vegetable and marine oils contains substances having a highantioxidant activity. I have found that the material can be employed asan antioxidant in the original condition in which it is removed from thedeodorizing equipment or it may be refined before use.

The most common method of deodorizing oils involves vacuum treatment inthe presence of steam. The vacuum is usually produced by means of asteam ejector and the steam is passed through the oil being refined. Thesteam which is passed through the oil is usually condensed in abarometric condenser and the condensed steam permitted to flow into asump or condenser discharge. I have found that scum having highantioxidant qualities or potency is produced in that it can be removedfrom mixed steamvapors, from the barometric condenser or from the sumpinto which the condenser discharges. The content of the scum inantioxidant potency vitamin E activity, and sterol and other accessorysubstance content is often many times that of the richest crude oilsfrom which it is derived. The scum is thus a valuable primaryconcentrate of accessory substances in spite of it having beenconsidered an annoying waste product for upwards of fifty years.

Many variations of the vacuum deodorizing method are employed by thedifferent oil manuiacturers and it is to be understood that my inventionis applicable to all methods of deodorization which involve the use ofincipient distillations in combination with a carrier gas,- and that myimproved antioxidant can be separated from the vapors or gases derivedfrom the refined oil.

Separation may be accomplished in the manner set forth above but it isequally feasible to separate the vapors, sludge or scum at intermediatestages such as between the deodorizing vessel and the evacuating pumpsby means of catching vessels or condensers. Such material is known asdeodorizer trap sludge. It is to be understood that the word scum asused herein shall include volatilized matter produced by each of theforegoing methods.

The antioxidant material is lighter than water and coats the surface ofthe condenser discharge or barometric sump with a thin scum. Thismaterial is known in industry as deodorizer hot well sludge. Incollecting the active material the simplest method employed is to skimthe substance from the surface or the water intermittently. It alsotends to collect on the walls of the tank and can be scraped therefrom.The discharge from the condenser is usually rather warm and thedischarge tank is often quite small. For this reason the scum may notseparate or considerable amounts of the active material remains insolution or suspension and flows to the waste discharge. I have foundthat the yield of active substance can be considerably increased bycompletely cooling the condenser discharge or the contents of thedischarge tank to approximately atmospheric temperature. The yield canalso be increased by substantially increasing the size of the dischargetank or even providing an outside pond to the still surface on which thescum can rise. The discharged condensate can also be treated with asolvent, scrubbers, or

relatively large amounts by this procedure and passed through filters orscreens. Any one or all of the foregoing expedients can be employed toimprove the yield of the active material.

The scum can somethnes be employed eilec- I tively as an antioxidant inits original condition,

or it may be subjected to a refining treatment to remove varioussubstances some of which are inert impurities and others of which havean antagonistic action to that of the antioxidant. In addition to theantioxidant the scum contains, among other materials, sterols, waxes,unsaturated hydrocarbons, free fatty acids, small amounts of unchangedoil and soaps formed by the reaction between the free fatty acids andthe dissolved solids which ordinarily occur in water. Calcium soaps areformed by this means and the antioxidant and the globules of oil, fattyacids, etc. are attracted to and precipitated in the calcium soaps. Thisproduct as removed from the deodorization procedure is a greasy, spongysubstance.

Numerous methods of refining are available but the ones which appear atthe present time to'ofier the best product are distillation, solventextraction, neutralization or saponiflcation or combinations thereofpreceded if necessary by a chemical treatment such as washing withmineral acid to remove iron or calcium soaps. Vacuum steam distillationanalogous to that employed in the original deodorization, yields adistillate of the antioxidants relatively free of fatty acids, sterols,etc. and substantially free of soaps. Ordinary vacuum distillation ofthe scum can be employed and at a temperature of 150 to 330 a fractionof high antioxidant potency is obtained. The scum may also be distilledin a molecular or similar still, under high vacuum, unobstructed pathdistillation conditions. A distillate having high antioxidant potency isobtained at about 120 to 220 C. The distillation treatment can bepreceded by neutralization of the soaps and this procedure is usuallydesirable.

A portion of the antioxidant substance becomes entrained in the soapsbut it has been found that solvents can be employed to extract theantioxidant therefrom. The solvent extract can then be distilled eitherto remove the solvent or to also distill oil the antioxidant from theaccompanying extracted materials.

The antioxidant of my invention, namely, the sludge or the refinedproducts derived therefrom, can be employed to stabilize a wide varietyof substances. For instance, it can be added to vitamin products, suchas fish oils and vitamin concentrates produced therefrom by high vacuumdistillation or saponification. It can be used in foods and in ediblesubstances in general. For instance it can be added to edible oils,shortenings, lard, margarines, etc. to protect them against rancidity.It can also be added to ,the fat employed to prepare foods such aspotato chips and the potato chips are stabilized there by. It is ofparticular interest; in connection with foods because the antioxidant isderived from natural animal and vegetable materials and its presence infoods therefore would be free of objection. The antioxidant can be addedto rubber, gasoline, or to crude materials treated to yield suchsubstances. The antioxidant has particular value for use in its crudecondition for processes wherein an oxidizable substance is treated orpurified, etc. For instance, if the crude sludg is added to a fish oilwhich is then subjected to alkali refining, followed by moleculardistillation, a distillate containing the vitamins of the fish oils andthe antioxidant f the sludge is obtained in relatively pure conditionvfree from impurities accompanying the antioxi- V dant in the originalsludge. This procedure has 1 the added advantage that the vitamin ispro.-- tected during the entire.treatment. If desired the antioxidantcan .be returned to the oilfrom which it was derived in the oilrefinery. In this way the'stability of the original oil is made tocompare favorably with that of the raw oil before it was introduced intothe refinery.

EXAHPLI 1 Treatment of corn oil deodorizer hotwell sludge to obtainmaterials of useful antioxidant value The sludge as recovered from thehotwell contains up to 50 per cent free fatty acids and seldom less than10 per cent. The pipes and ves sels are generally made of iron and thewater from the ejector barometric leg generally contains calcium. Thesludge, therefore, contains calcium and iron salts, the latter beingespecially detrimental to its use as an antioxidant. As a first stage inrefining, the sludge may be'melted, the water separated, and then wetfiltered from the debris and much of the soaps. Alternatively, thesludge may be melted, much of the water drained away, and the residuetreate with an organic or inorganic acid, which may be acetic or someother strong organic acid, sulfuric, hydrochloric or other acid ivingsoluble calcium and iron salts; sulfuric is widely used to liberate freefatty acidsfrom crude soapstocks but hydrochloric acid is the preferredacid for my purpose.

ExAMPLn 1A gallons of corn oil deodorizer sludge were treated with 12gallons of commercial concentrated hydrochloric acid and the mixturebrought EXAMPLE 1B Before or during the boiling with hydrochloric acidas in Example la, zinc dust was added in the proportion of 5 pounds to100 gallons of oil. This resulted in a marked reduction in the. color.and the tocopherol quinones present were altered to the reduced form ofthe substance. The oil was worked up as before. Other metals which reactwith acid to give nascent hydrogen, such as iron, can be used in placeof zinc. The tocopherol in vegetable oil is present in the form of thequinone and hydroquinone. Losses during distillation are much less withthe hydroquinone form so that reduction of the quinone to thehydroquinone substantially reduces loss during subsequent proceduressuch as distillation.

EXAMPLE 1C The oil from any of the above examples was placed in a vacuumdeodorizing kettle and the process of deodorization carried out withsteam at a pressure of .1 mm. and a temperature of C. After three hoursmost of the volatile fatty acids had been removed, leaving substantiallyall of the gamma tocopherol in the kettle. The material was withdrawnand allowed to stand at a temperature near the setting point of the massfor two days, during which time a large quantity of vegetable sterolsseparated and were filtered oil. The liquid portion was found to contain2% per cent gamma tocopherol and had an acid value of 4. It was foundsuitable for addition to lard, edible vegetable oils, and vitaminbearingproducts for the purpose of stabilization.

EXAMPLE 1D The oil from'the preceding example instead of being withdrawnfrom the still after subjection to a temperature of 130 C. was continuedunder vacuum with the passage of steam while the temperature was raisedto 170 C. Material which contained per cent free fatty acid andapproximately 10 per cent tocopherol was collected from the barometricleg.

This material was worked up separately for the production of puretocopherol, or alternatively it was returned to new batches ofacid-treated sludge prior to deodorization. The temperature was nowraised to 200 C., and a quantity of hotwell sludge collected which wassubstantially free from fatty acid and contained per cent gammatocopherol. This material was entirely suitable for adding to margarine,salad oils, etc., for the purpose of stabilization. The temperature wasthen raised to 250 C. and a further portion of tocopherol sludgerecovered. By an alternative procedure a surface condenser was placedbetween the deodorizer and the steam ejector, and. the materialscollected here instead of as hotwell sludge. The residue from the finaldeodorization process was found to be a dark, neutral fat. This waspassed through bleaching earth and was added to a batch of crude oilabout to pass through the plant on the normal cycle of refiningoperations.

EXAMPLE 115:

In this example the sludge is treated exactly as in the foregoingexample except that it is placed in the deodorizing kettle without anyprevious acid or other treatment except as a convenience for the removalof most of the water.

, EXAMPLE 2A Recovery of tocopherol from hotwell sludge obtained fromthe deodorization of sog/bean oil Sludge is given acid treatment as inthe previous example and is placed in a large vacuum kettle under avacuum of 1 mm. of mercury. The temperature is raised to about 100, anda quantity of distillate withdrawn which smells strongly of terpenes. Itcontains free fatty acids and at least two unsaturated hydrocarbons. Thefatty acids can be separated by crystallization or neutralization, andthe hydrocarbons further purified by distillation. The temperature isnow raised to 150 when,more hydrocarbons of a similar nature come overtogether with a liberal proportion of free fatty acids. The temperatureis now raised to 200 C., and the pressure reduced to .1 mm. A mixture ofresidual free fatty acids comes over containing a mixture of alpha andgamma tocopherols. The distillate is cooled to separate the majority ofacids, and the liquid filtered oflf containing 5-10 per centtocopherols. The temperature is raised and further quantities oftocopherol solution substantially free from free fatty acids areremoved. This solution may contain as much as per cent mixed alpha andgamma tocopherols. It is suitable for employment as such in medicinalpreparations for vitamin E activity or for the stabilizing of oils andfoods, or the distillates may be further worked up to produce thefurther tocopherol or tocopherol palmitate.

All the distillates from this example when cooled separate into liquidand solid portions. Besides free fatty acids, a mixture of sterols whichmay contain as much as 50 per cent stigmasterol can be separated.Stigmasterol may be separated from this crude sterol by the preparationof the tetra-bromides, with subsequent hydrolysis. The residue left inthe still is a low grade fat, the quality of which, however, is muchhigher than contained in the original sludge. It may be returned to therefinery cycle or may be used directly as a low grade fat.

EXAMPLE 2B The acid-treated sludge after treatment in a vacuum still atas in the above example, may be transferred to a batch molecular stillor a continuous molecular still or any form of high vacuum unobstructedor short-path still or to a continuous high-vacuum column still,- andthe tocopherols removed from the majority of the other constituents.Thus the oil may be passed over the rotating plate of a centrifugalunobstructed path still operating at a pressure of three microns. Themajority of the tocopherols will distill at 180 C. or between the limits130- 230 C. There will result a distillate containing from 10-30 percent alpha and gamma tocopherols. Where a grid or other fractionatingdevice is employed, as in Patent 2,180,052 to Hickman and Hecker,concentrations as high as 50-60 per cent tocopherols may be obtained.

EXAMPLE 3 Alpha tocopherol from cottonseed deodorizer trap sludge Thetrap sludge is melted and filtered. If the fatty acid content is below10 per cent, the fat is given an alkali refining at this stage. Ineither case, the melted sludge is allowed to enter a vacuum degasser at90 C. at a pressure of 10 mm. Volatile hydrocarbons and terpenes areseparated in an attached condenser. The degassed liquid is now allowedto enter the center of a long countercurrent fractionating distillationcolumn, which column is the middle one of a series of several columns,maintained under a vacuum of 50 microns at the top and 3 inm. at thebottom end. The bottom end is maintained at temperatures ranging from to270 C. The columns have substantially unobstructed paths, between thevaporizing and condensing surfaces. From the first column, fatty acidsand hydrocarbons are withdrawn; from the second, hydrocarbons; and fromthe third, a distillate of tocopherol which is substantially more potentthan could be secured from a single molecular distillation. Thisapparatus with column still is described in detail in my application187,454 filed 1/28/38.

EXAMPLE 4 Use of crude scam to stabilize vitamins during refining 5parts of a deodorizer scum containing 2 per cent tocopherol is added to97 parts of grayfishliver oil containing 15,000 units per gram vitaminA, and the mixture is given alkali refining. It is then distilled, underhigh vacuum, unobstructed path conditions yielding a fraction containing230,000 units per gram of vitamin A and 1-1.5 per cent tocopherol. Thisrepresents a higher concentration of tocopherol than could be obtainedby distilling a blend of grayfishliver oil and 25 per cent of an averagequality crude corn oil.

EXAMPLE 5 parts of deodorizer scum are intimately mixed with 90 partsshark stearine containing 100,000 units of vitamin A per gram. Themixture is alkali refined, filtered, and distilled as in Example 4. Adistillate is secured containing 80 per cent of the vitamin A in aconcentration above three-quarters of a million units per gram and inthe same concentrate there is between 2-4 per cent by weight oftocopherol.

EXAMPLE 6 Stabilization of vitamins Sardine oil is vacuum distilled toyield a concentrate containing 500 units per gram of vitamin D and 3,000units per gram vitamin. A. To 90 parts of this mixture is added 10 partsof neutralized and filtered deodorizer scum. The mixture is used as astable vitamin feed for chickens.

EXAMPLE '7 Stabilization of rubber A low temperature distillate oftocopherol from one of the proceding examples containing too much odorand fatty acid to be readily acceptable for edible purposes is added toa rubber mix on the incorporating rolls in a rubber mill in theproportion of one part of distillate to 100 parts of rubber. The mixtureis finished and moulded into commercial articles in the ordinary way.

EXAMPLE 9 Stabilization of lard I One part of odorless distillateprepared as in the foregoing examples and containing approx-.

imately per cent tocopherol is adde to 200 parts of lard and thoroughlymixed and the mixture placed in containers for the commercial market.

EXAMPLE 10 Stabilization of hardened fat One part of steam deodorizedsludge prepared as in Example 1c, substantially free from taste and odoris added to parts of a hydrogenated cottonseed frying oil and is usedfor the frying of chipped potatoes.

In all the previous examples the starting mate-' rials and the methodsof processing are interchangeable. Thus, the first examples have beengiven in connection with gamma tocopherol and corn oil, and the lastwith alpha tocopherol and cottonseed oil. Nevertheless, any one of thesludges could be handled according to any of the examples. It is evidentthat during the hendling oi the sludge oxidation may occur. Icontemplate the quick collection oi the sludge, the storage andprocessing where desirable, in vacuum or in inert atmosphere, and Icontemplate correcting the effects of oxygen by wet reduction orhydrogenation at any stage during the concentration.

'Ilhe distillation temperature of the sterols which are contained in thesludges in a. little lowerthan that of the tocopherols. If. therefore,the temperature of the deodorizer trap or pipe lines is relatively low,tocopherol may collect in these preferentially, while the sterols passinto the hotwell sludge. The ratio of fat to sterol in trap sludge orhotwell sludge is very variable and in certain cases, namely, thedeodorization of corn oil, so much sterol may accumulate in the hotwellsludge that it will not go into solution when the fat is melted duringrendering. These sterols may be separated from the fat by pressing atthe lowest temperature at which the fat will melt. The rest of thesterols can be separated from the distillate and/or fromthe distillandduring various parts of the vacuum treatment. Thus, if, much volatilehydrocarbons and low-boiling fatty acids are present, removalof these bydistillation leaves a distilland so rich in sterols that these willcrystallize out on cooling. If, however, there are few volatilematerials, the sterols may appear substantially concentrated in thetocopherol distillates, particularly those coming over at the lowertemperatures. The distillates, therefore, are filtered and the crudesterols removed. The sterols may be further purified by crystallizationfrom a Polar solvent such as methyl acetate, ethyl formate, or methylalcohol, but any other solvents such as light petroleum, the chlorinatedsolvents or even fats may be used. The sterols may be separatedpartially from one another by crystallization or absorption, or theunsaturated sterol may be separated completely by bromination. Thesesterols in crude or refined condition may be employed for thepreparation of synthetic medicinals. For instance the stigmasterol whichis separated from the sludge by the foregoing methods may be used toprepare synthetic hormones.

Due to the high stability of vitamin concentrates which are stabilizedby this antioxidant, they can be disposed in animal foodstuffs withoutsubstantial loss. Heretofore this has been unsatisfactory procedurebecause the vitamin is necessarily exposed to atmospheric oxygen whendistributed in the foods in this manner.

Rapid loss was a consequence. However, with my highly active antioxidantthis procedure is feasible and little 1055 results therefrom.

The active material can be obtained in the manner described from thesludges and the like derived from any natural animal oil or fat or thelike which contains the tocopherols. However, all oils do not contain itand for this reason all distillate by-products can not be used. Forinstance sesame seed oil in its originalcondition or in hydrogenatedcondition is free of this material. However, I have found that most ofthese oils and fats do contain these substances and do yield highlypotent wastes. Oils which give particularly active waste are com, soybean and cotton seed oils.

Since each stage in th refining treatment of an oil results inadditional destruction of the antioxidant, I have found that it is bestto modify the conventional refining scheme so that the deodorizationstep takes place at the first of the procedure and is then followed bythe other refining steps such as alkali refining hydrogenatlon,bleaching, etc. In this way the original antioxidant content of the oilis available for recovering in the manner described.

By another modification I have found that it is feasible to recover theantioxidant of my inven-' tion by providing means for collecting vaporsremoved from paint or drying oils, such as linseed oil, during thebodying or polymerization step in paint oil manufacture. If desired,steam may be blown through the oil and/or vacuum may be applied. In theconventional polymerization procedure heretofore employed the activesubstance has been either decomposed completely or has been dischargedinto the atmosphere. The antioxidants are definitely detrimental to thedrying oil and their removal is advantageous for this reason and alsofor the reason that the polymerization rate is increased.

I am aware of Patent 2,095,740 which describes the use of a heavier thanwater steam distillate oi hydrogenated sesame seed oil. However, thereis considerable disagreement as to whether sesame oil containstocopherol. Authorities do agree that if any tocopherol is present insesame oil it is present in minute amounts which are negligible comparedwith the amounts of tocopherol occurring in other oils such ascottonseed or wheat germ oils. Also, it is conventional procedure whenpreparing a commercial deodorized, hydrogenated sesame oil to firstsubject the undeodorized, unhydrogenated sesame oil to alkali refining,washing, vacuum-drying and bleaching. Oil treated in this manner is thenhydrogenated, is re-refined with dilute caustic soda solution, washed,dried, filtered and possibly again bleached if the color is notsatisfactory. It is clear that any tocopherol which might be present insesame oil would be destroyed by this treatment which will take placeprior to deodorization. The present invention does not relate tohydrogenated sesame oil and also does not relate to a heavier-than-watermaterial. On the contrary it relates to a lighterthan-water scrum whichcontains a lighter-thanwater agent, namely tocopherol.

Reference is made to Hickman application 354,113, filed August 24, 1940,relating to separation of tocopherol from scum by chemical treatment,especially saponification followed by solvent extraction; to Baxterapplication 354,859, filed August 30, 1940, relating to preparation oftocopherol having improved color and stability by esterificatlon oideodorizer scum containing tocopherol in the presence of an amine and inthe presence of a strong reducing agent; to Hickman et 9.]. application358,270, filed September 25, 1940, which relates to the purification oftocopherol containedin scum the purificathe fat a lighter-than-watercomplex organic mixture which includes tocopherol and separatingtocopherol in concentrated form from this lighter-than-water mixture.

2. The process of preparing a tocopherol con-' centrate which comprisesin combination sub- Jecting a tocopherol-containing vegetable or animalfat, other than hydrogenated sesame oil, to vacuum deodorization withsteam, removing from the steam or steam condensate after the steam haspassed through the fat a lighter-than-water complex organic mixturewhich includes tocopherol and separating tocopherol in concentrated formfrom. the said lighter-than-water organic mixture. r

3. The process for preparing a tocopherol concentrate'which comprisesseparating tocopherol in concentrated form from a lighter-than-watermaterial vfliich contains a complex mixture of organic compoundsincluding tocopherol and which is obtained from the inert gas after ithas been passed through a tocopherol-containing vegetable or animal fat,other than hydrogenated sesame oil, during vacuum-inert 'gasdeodorization. 4

4. The process for preparing a tocopherol concentrate which comprisesseparating tocopherol in concentrated form from a lighter-than-watermaterial which contains a complex mixture of organic compounds includingtocopherol and which is obtained from the steam or steam condensateafter the steam has been passed through a tocopherol-containingvegetable or animal fat, other than hydrogenated sesame oil, duringvacuum-steam deodorization.

5. The process for preparing a tocopherol concentrate which comprisesseparating water from a complex organic mixture which containstocopherol, which mixture is lighter than water and is obtained from thesteam or steam condensate after the steam has been passed'through atocotion being simultaneous to a reduction treatpherol-containingvegetable or animal fat, other than hydrogenated sesame oil, duringvacuumsteam deodorization, and then separating tocopherol inconcentrated form from the substantially water-free complex organicmixture.

6. The process for preparinga tocopherol concentrate which comprisesheating a complex organic mixture which contains tocopherol, whichmixture is lighter than water and is obtained from the steam or steamcondensate after the steam has been passed through atocopherolcontaining vegetable or animal fat, other than hydrogenatedsesame oil, during vacuum-steam deodorization, stratifying the heatedcomplex organic mixture to form an upper oil-like layer .and a loweraqueous layer, separating the oil-like layer, subjecting it to vacuumdistillation and separating a fraction which contains tocopherol inconcentrated form.

7. The process for preparing a tocopherol concentrate which comprises incombination separating free fatty acids from a complex organic mixturewhich contains tocopherol, which mixture is lighter than water and isobtained from the steam or steam condensate after the steam has beenpassed through a tocopherol-containing vegetable or animal fat, otherthan hydrogenated sesame oil, during vacuum-steam deodorization and thenseparating tocopherol in concentrated form from the substantiallyacid-free complex organic mixture.

8. The process for preparing a tocopherol concentrate which comprises incombination acidifying a complex organic mixture which containstocopherol, which mixture is lighter than water and is obtained from thesteam or steam condensate after the steam has been passed through atocopherol-containing vegetable or animal fat, other than hydrogenatedsesame oil, during vacuum-steam deodorization, allowing the acidifiedmixture to stratify and then separating the upper tat layer from thelower acid layer.

9. The process for preparing a tocopherol concentrate which comprisessubjecting a lighterthan-water material, which contains a complexmixture of organic compounds, including tocopherol and which is obtainedfrom the inert gas after it has been passed through atocopherolcontaining vegetable or animal fat, other than hydrogenatedsesame seed oil, during vacuuminert gas deodorization to vacuumdistillation and separating a distillation product containing tocopherolin concentrated form.

10. The process for preparing a tocopherol concentrate which comprisessubjecting a lighterthan-water material, which contains a complexmixture of organic compounds, including tocopherol and which is obtainedfrom the inert gas after it has been passed through atocopherolcontaining vegetable or animal fat, other than hydrogenatedsesame seed oil, during vacuuminert gas deodorization to vacuumdistillation and separating a distillate which contains a relativelyhigh content of tocopherol.

11. The process for preparing a tocopherol concentrate which comprisessubjecting a lighterthan-water material, which contains a complexmixture of organic compounds, including tocopherol and which is obtainedfrom the inert gas after it has been passed through atocopherolcontaining vegetable or animal fat, other than hydrogenatedsesame seed oil, during vacuuminert deodorization to vacuum-steamdistillation and separating impurities as a distillate and purifled andconcentrated tocopherol concentrate as an undistilled residue.

12. The process for preparing a tocopherol concentrate which comprisessubjecting a lighterthan-water material which contains a complex mixtureof organic compounds, including tocopherol and which is-obtained fromthe inert gas after it has been passed through a tocopherolcontainingvegetable or animal fat, other than hydrogenated sesame seed oil, duringvacuuminert deodorization to vacuum-steam distillation and separating adistillate which contains a relatively high content of tocopherol.

13. The process for preparing a tocopherol concentrate which comprisessubjecting a lighterthan-water material which contains a complex mixtureof organic compounds including tocopherol and which is obtained from theinert gas after it has been passed through a tocopherolcontainingvegetable or animal fat, other than hydrogenated sesame seed oil, duringvacuuminert deodorization to high vacuum unobstructed path distillationand separating a distillate which contains a relatively high content oftocopherol.

KENNETH C. D. HICKMAN.

